Some people are at risk of having a heart attack or stroke due to fatty plaque buildups in their arteries that restrict the flow of blood or even break off and block the flow of blood completely. A number of intravascular procedures have the potential to treat those plaque buildups. For example, angioplasty involves delivering a balloon or a stent to open up the constricted blood vessel. This procedure involves inserting a thin catheter into the patient's vessel and navigating it to the affected site.
Where the plaque has built up to the point that it effectively closes off the vessel, the affected site is sometimes referred to as a chronic total occlusion. Such an occlusion can be treated by a catheter with a mechanism at the tip that is designed to ablate the plaque, opening a hole through the occlusion, allowing the person's blood to flow and carry oxygen and nutrients throughout the body.
Using a catheter in an intravascular intervention to treat plaque buildup carries some risks and difficulties. The blood vessels define a convoluted and intricate network. Simply navigating a catheter to the correct site from outside the body can be very difficult. Even where a branch in the vessel can be seen from outside of the body by x-ray, steering a catheter down the right branch can be a significant challenge. Using an ablation mechanism to cut through an occlusion requires the utmost precision. Ablation can use lasers, RF waves, or mechanical cutters to cut up the plaque, and those cutter mechanisms operate within fractions of a millimeter of the walls of a person's blood vessels. It requires exacting precision to ablate plaque properly.